Safety and effectiveness of controlled-release paroxetine in routine clinical practice: results of a postmarketing surveillance study of patients with depression

OBJECTIVE: Selective serotonin reuptake inhibitors are commonly used in the pharmacotherapy of depression. However, adverse events can lead to their early discontinuation. This study evaluated the safety and effectiveness of paroxetine controlled-release (CR) tablets in Japanese patients with depression/depressive state (hereafter referred to as depression) in routine clinical practice in Japan. PATIENTS AND METHODS: This was an open-label, noninterventional, prospective, postmarketing surveillance study. A total of 3,213 patients aged 12–92 years with depression were prescribed paroxetine CR for 8 weeks at the physician’s discretion. Safety was evaluated on the basis of the reporting of adverse drug reactions. Effectiveness was evaluated on the basis of the physician’s assessment using the Clinical Global Impression-Global Improvement (CGI-GI) and the Clinical Global Impression-Severity of Illness (CGI-SI) scales, as well as on the basis of the patients’ self-reported satisfaction. The primary effectiveness outcome was the improvement rate based on the physician’s assessment using the CGI-GI. RESULTS: The incidence of adverse drug reactions was 11.2% (359/3,213; 95% confidence interval [CI]: 10.1%–12.3%). The common adverse drug reactions that accounted for 1.0% or more of the incidence were nausea (3.5%) and somnolence (2.7%). The proportion of patients who continued paroxetine CR at week 8 was 80.2% (2,577/3,213; 95% CI: 78.8%–81.6%). The improvement rate at week 8 (last observation carried forward) was 72.8% (2,132/2,927; 95% CI: 71.2%–74.4%). The proportion of patients with CGI-SI scores of moderately or severely ill decreased from 63.6% at baseline to 17.9% at week 8. The proportion of patients who were satisfied with paroxetine CR treatment was 69.8% (2,040/2,921; 95% CI: 68.1%–71.5%). CONCLUSION: The results of this study suggest that paroxetine CR is a well-tolerated and efficacious treatment for depression in routine clinical practice.